docs: def topo(tess, registrations, properties=None, meta_data=None, chirality=None):
      '''
      topo(tess, regs) yields a Topology object with the given tesselation object tess and the given
        registration map regs.
      '''
      return Topology(tess, registrations, properties=properties, meta_data=meta_data,
                      chirarality=chirality)